The present invention is related to an apparatus for stopping and releasing the movement of a sliding up-and-down pole of a portable motion picture screen stand which makes it possible to carry out smooth operation of the sliding pole designed to go up and down inside the hollow supporting cylinder of a portable motion picture screen stand with a tripod, by turning linked gears mounted on the supporting plates fixed to an appropriate part of the hollow supporting cylinder, and which also makes it possible to hold the sliding pole at an optional position on its way up or down by a hooking device and to stop the turning of the linked gears.
Conventional apparatuses for stopping and releasing the movement of a sliding up-and-down pole of a portable motion picture screen stand have disadvantages; their devices for adjusting the position of the sliding pole optionally against the hollow supporting cylinder is complicated or the up and down movement of the sliding pole is operated by the turning of only one gear and, accordingly, much labour is required for operation.
The present invention has improved the abovementioned disadvantages and, moreover, has made it possible by a simple mechaism to let the sliding pole go up and down smoothly inside the hollow supporting cylinder in accordance with the stopping and releasing operation of the sliding pole at an optional position against the hollow supporting cylinder.